Hi, I'm very new to this and I have some questions about getting this set up for my incoming AKG K7XX. Please don't shout at me XD.
I bought a DACport Slim on the first run and have not really used it since as my headset pretty much died right after the DACport Slim arrived >.<
so questions,
1: I have to update the firmware according to what I've read in the other comments. Is there anything I should really/especially watch out for? Also, where can i get the files?
2: I have on my pc Realtek HD Audio and Razer Surround. should I remove them? Razer Surround was mainly to easily switch audio output between headphone and speakers, and Realtek was just there.
3: There was some conversation about setting pc volume to max and using the Dacport to control the headset volume. Is that what I should do?
Thanks for the helps! Please~

1. Make sure you can find a computer which works with the slim already. You can find the firmware update on centrance's DACport page.
2. Should be OK with them installed.
3. Theoretically it's better. Windows outputs the highest quality at the highest volume, but my ears don't hear any difference.

In regards to sound volume in windows:
It is actually kinda complex wrapping ones head around it for most especially those who have not used a DAW. As it turns out , setting the DACport to 96khz sample rate 24 bit or 32bit(dacport) "Default device" in control panel helps overcome windows directsound conversion in win vista and above.(i'm certain in win 7)
The concept of bit dithering for volume change suggests to run volume at max in windows and just control your volume level via external amplifier to easily overcome this in all versions of Windows.
It is generally best to play 16bit or 24bit audio running the DACport in "exclusive access" in ASIO or WASAPI media player because it prevents windows from effecting the "bits" through its "Directsound" audio engine.
I recommend playing music in Jriver with its "bitperfect" 64bit internal volume control as it more user friendly initially but Foobar is free with 32bit internal volume control and is equal in many ways, just requires more elbow grease at first. It is also generally advised to let the media play at its Native sample rate. The internal volume control of Jriver and Foobar work pretty good as they correctly shift the bits for volume control until you get "too quiet" and chop off bottom with 24bit media in foobars 32bit volume control at -48db.(non -issue with 16bit in foobar)
Same applies to 16bit media and any 24bit volume control output being -48db before any effect happens at the lowest db point. So quiet you likely wont hear any difference.
Another factor is also the use of the internal digital attenuation control of the DACports volume pot of the AKM4490 chip. It is a 256 step .5db internal attenuation. Likely excellent as it is internal in the Dac and not a separate circuit or device but purists might want 100% volume to prevent any effect. (AKM and CEntrance did it right) No boost switch is Unity gain with pot at 100%. Effectively only hearing the DAC pure. So far it has been enough for all headphones I have tried granted I myself run the DACport in high boost for "pro level" active monitors and just turn the volume down in Jriver when I plug in headphones as I do not like flipping the switch as I have to get a tool out to do so.
The simple answer is just bypass "Directsound" with ASIO or WASAPI mode whenever possible when listening to audio and use a Media player with 32bit or greater volume control.
I also got in on the Red/Blk AKG7XX myself. Not really a headphone enthusiast as I prefer a true linear flat frequency playback from balanced loudspeakers in a treated room at around 85db.(20-23khz FR +- 1db - gets real tough below 40-50hz). But from what I gather the AKG7XX is one of the "flatter" sets with great resolution.
Enjoy your combo!

Wow. Thanks for the effort. Unfortunately I don't understand most of what you said even after reading through it twice XD. I will need to look up many of the things you mentioned to even know what it means which I will in a couple of days on my rest day. =D

Oops I get carried away sometimes. Wifey just read through it too and pointed out it that I thoroughly explained the "why" and reasons of technicality more so than "how" to set things up to get good results. She insisted I clarify :)
In Windows control panel/hardware and sound/sound: set your sample rate on the "CEntrance USB Audio" properties Default Format to 96khz at 32bit. Also select both boxes under "allow exclusive mode."
The 96khz 24 or 32 bit is the format least effected by Windows Audio API. That setting is what I use for games and just use the volume control on my keyboard.
I recommend getting the media players Foobar for Free or Jriver for music as they both have excellent volume control technology and other cool DSP features, EQs, sound calibration as well as plugins like RTA (real time analyzer).
One approach would be to run the CEntrance at low gain 100% volume (line level) and use the Pc to control volume levels through your chosen Media player program in WASAPI or ASIO mode. (Jriver or Foobar) They are device settings configurable in both programs and you need to enable "internal volume control".
Your second approach would be to put Windows volume at 100% (using 96khz 32bit) and control volume by way of DACport's physical volume dial.
You do not have to remove Realtek or Razer. Just make CEntrance Default sound driver.
Use the approach for what physically works best for you.